Exam Revision Q&A

Ask a question to be in with the chance of winning a £50 Amazon voucher. Answer a question to be in with the chance of winning a £100 Amazon voucher!

Notifications

Clear all

Protons and neurons not equal (periodic table)

Last Post

RSS

15/12/2017 9:00 pm

Topic starter

I have seen in some practice questions i have tried photon and neutron numbers varying with that listed on the periodic table. Why does this happen?

Alf

(@alf)

New Member

| 1 Posts
1 0 0

Add a comment

1 Answer

21/12/2017 8:20 pm

Hi Alf

The number of neutrons in different isotopes of the same atom can vary which would explain the varying mass numbers you are seeing.

mass number = number of protons + number of neutrons

Isotopes are atoms which have the same atomic number (number of protons) but a different mass number due to there being a different number of neutrons in each isotope of the element.

There is no rule stating that the number protons and neutrons in an atomic element must be equal. I am not sure what you mean by proton number varying with that listed. Atoms of the same element have the same number of protons, so this could be a mistake in the practice questions.

Admin

(@admin)

Member Admin

| 4 Posts
0 4 0

Add a comment

Percentage
I would need help in working out a percentage, i really...
By Damilola, 2 years ago
Assessment Objectives
What do AOs 3 and 4 basically mean/ask for? ?
By 19dunder, 2 years ago
History Studying
How would you study for History GCSE? What is the best ...
By historymaster, 2 years ago
MSc research proposal - advice
Hi, I have to propose a topic for my MSc thesis researc...
By JesseVoss, 3 years ago
Geographic coordinates
Hi, In my opinion, very useful tool in many possible ...
By JesseVoss, 3 years ago
Geographic coordinates
Hi, In my opinion, very useful tool in many possible ...
By JesseVoss, 3 years ago
Enthalpy, Hess' law and cycles
Hi, I'm really struggling with this question... : Hydro...
By MaddieBudd, 3 years ago
Answer to: A-LEVEL MOCKS
Hi Unity100, There are many effective ways you could go...
By Admin, 3 years ago
A-LEVEL MOCKS
How do l remember all the positive and negative externa...
By Unity100, 3 years ago

Super Globals

Requests: Array ( [woocommerce-login-nonce] => [_wpnonce] => [woocommerce-reset-password-nonce] => [woocommerce-edit-address-nonce] => [save-account-details-nonce] => )

Server: Array ( [woocommerce-login-nonce] => [_wpnonce] => [woocommerce-reset-password-nonce] => [woocommerce-edit-address-nonce] => [save-account-details-nonce] => )

Options and Features

permastruct: questions
use_home_url: 0
url: https://studywise.co.uk/questions/
Array
(
    [title] => StudyWise Exam Revision Q&A Forum
    [description] => StudyWise Question & Answer Help Forum. Ask Questions. Exchange Answers. Any questions related to students life welcome! #exams #revision #alevel #gcse #uni
    [lang] => 1
    [menu_position] => 23
)
pageid:8277
default_groupid: 3
Array
(
    [layout_qa_intro_topics_toggle] => 1
    [layout_extended_intro_topics_toggle] => 1
    [layout_qa_intro_topics_count] => 3
    [layout_extended_intro_topics_count] => 5
    [layout_qa_intro_topics_length] => 90
    [layout_extended_intro_topics_length] => 45
    [display_current_viewers] => 1
    [layout_threaded_intro_topics_toggle] => 0
    [layout_threaded_display_subforums] => 1
    [layout_threaded_intro_topics_count] => 10
    [layout_threaded_intro_topics_length] => 0
    [layout_threaded_filter_buttons] => 1
    [layout_threaded_add_topic_button] => 1
)
Array
(
    [layout_extended_intro_posts_toggle] => 1
    [layout_extended_intro_posts_count] => 4
    [layout_extended_intro_posts_length] => 50
    [recent_posts_type] => topics
    [tags] => 1
    [max_tags] => 5
    [tags_per_page] => 100
    [topics_per_page] => 10
    [edit_topic] => 1
    [edit_post] => 1
    [eot_durr] => 300
    [dot_durr] => 300
    [posts_per_page] => 15
    [eor_durr] => 300
    [dor_durr] => 300
    [max_upload_size] => 5242880
    [display_current_viewers] => 1
    [display_recent_viewers] => 1
    [display_admin_viewers] => 1
    [attach_cant_view_msg] => You are not permitted to view this attachment
    [layout_threaded_posts_per_page] => 5
    [layout_qa_posts_per_page] => 15
    [layout_qa_comments_limit_count] => 3
    [layout_qa_first_post_reply] => 1
    [layout_threaded_nesting_level] => 5
    [layout_threaded_first_post_reply] => 0
    [union_first_post] => Array
        (
            [1] => 0
            [2] => 0
            [3] => 1
            [4] => 0
        )

[search_max_results] => 100
    [topic_body_min_length] => 2
    [topic_body_max_length] => 0
    [post_body_min_length] => 2
    [post_body_max_length] => 0
    [comment_body_min_length] => 2
    [comment_body_max_length] => 0
)
Array
(
    [custom_title_is_on] => 1
    [default_title] => Member
    [members_per_page] => 15
    [online_status_timeout] => 240
    [url_structure] => nicename
    [search_type] => search
    [login_url] => /login/
    [register_url] => /register/
    [lost_password_url] => /password-reset/
    [redirect_url_after_login] => 
    [redirect_url_after_register] => 
    [redirect_url_after_confirm_sbscrb] => 
    [title_usergroup] => Array
        (
            [1] => 1
            [5] => 1
            [4] => 1
            [2] => 1
        )

[title_second_usergroup] => Array
        (
            [1] => 0
            [5] => 0
            [4] => 0
            [2] => 0
            [3] => 1
        )

[rating] => Array
        (
            [0] => Array
                (
                    [points] => 0
                    [title] => New Member
                    [color] => #d2d2d2
                    [icon] => fa-star-half-o
                )

[1] => Array
                (
                    [points] => 5
                    [title] => Active Member
                    [color] => #4dca5c
                    [icon] => fa-star
                )

[2] => Array
                (
                    [points] => 20
                    [title] => Eminent Member
                    [color] => #4dca5c
                    [icon] => fa-star
                )

[3] => Array
                (
                    [points] => 50
                    [title] => Trusted Member
                    [color] => #4dca5c
                    [icon] => fa-star
                )

[4] => Array
                (
                    [points] => 100
                    [title] => Estimable Member
                    [color] => #4dca5c
                    [icon] => fa-star
                )

[5] => Array
                (
                    [points] => 250
                    [title] => Reputable  Member
                    [color] => #4dca5c
                    [icon] => fa-star
                )

[6] => Array
                (
                    [points] => 500
                    [title] => Honorable Member
                    [color] => #e5d600
                    [icon] => fa-certificate
                )

[7] => Array
                (
                    [points] => 750
                    [title] => Prominent Member
                    [color] => #e5d600
                    [icon] => fa-certificate
                )

[8] => Array
                (
                    [points] => 1000
                    [title] => Noble Member
                    [color] => #e5d600
                    [icon] => fa-certificate
                )

[9] => Array
                (
                    [points] => 2500
                    [title] => Famed Member
                    [color] => #ff812d
                    [icon] => fa-shield
                )

[10] => Array
                (
                    [points] => 5000
                    [title] => Illustrious Member
                    [color] => #e04a47
                    [icon] => fa-trophy
                )

)

[rating_title_ug] => Array
        (
            [5] => 1
            [4] => 1
            [3] => 1
        )

[rating_badge_ug] => Array
        (
            [1] => 1
            [5] => 1
            [4] => 1
            [2] => 1
            [3] => 1
        )

)
Array
(
 [from_name] => StudyWise Q&A
 [from_email] => info@studywise.co.uk
 [admin_emails] => philip.houseley@gmail.com
 [new_topic_notify] => 1
 [new_reply_notify] => 1
 [confirmation_email_subject] => Please confirm subscription to [entry_title]
 [confirmation_email_message] => Hello [member_name]! 
 Thank you for subscribing. 
 This is an automated response. 
 We are glad to inform you that after confirmation you will get updates from - [entry_title]. 
 Please click on link below to complete this step. 
 [confirm_link]
 [new_topic_notification_email_subject] => New Topic
 [new_topic_notification_email_message] => Hello [member_name]! 
 New topic has been created on your subscribed forum - [forum].
 
 [topic_title]
 <blockquote>
 [topic_desc]
 </blockquote>
 <hr>
 If you want to unsubscribe from this forum please use the link below. 
 [unsubscribe_link]
 [new_post_notification_email_subject] => New Reply
 [new_post_notification_email_message] => Hello [member_name]! 
 New reply has been posted on your subscribed topic - [topic].
 
 [reply_title]
 <blockquote >
 [reply_desc]
 </blockquote>
 <hr>
 If you want to unsubscribe from this topic please use the link below. 
 [unsubscribe_link]
 [report_email_subject] => Forum Post Report
 [report_email_message] => Report details:
 Reporter: [reporter], 
 Message: [message], 
 
 [post_url]
 [wp_new_user_notification_email_admin_subject] => [blogname] New User Registration
 [wp_new_user_notification_email_admin_message] => New user registration on your site [blogname]:

Username: [user_login]

Email: [user_email]

[wp_new_user_notification_email_subject] => [blogname] Your username and password info
    [wp_new_user_notification_email_message] => Username: [user_login]

To set your password, visit the following address:

[set_password_url]

[reset_password_email_message] => Hello!

You asked us to reset your password for your account using the email address [user_login].

If this was a mistake, or you didn't ask for a password reset, just ignore this email and nothing will happen.

To reset your password, visit the following address:

[reset_password_url]

Thanks!
 [update] => 1
 [user_mention_notify] => 1
 [user_mention_email_subject] => You have been mentioned in forum post
 [user_mention_email_message] => Hi [mentioned-user-name]! 
 You have been mentioned in a post on "[topic-title]" by [author-user-name].

Post URL: [post-url]
    [overwrite_new_user_notification_admin] => 1
    [overwrite_new_user_notification] => 1
    [overwrite_reset_password_email_message] => 1
)
Array
(
    [user-admin-bar] => 0
    [page-title] => 1
    [top-bar] => 1
    [top-bar-search] => 1
    [breadcrumb] => 1
    [footer-stat] => 0
    [mention-nicknames] => 1
    [content-do_shortcode] => 0
    [view-logging] => 1
    [track-logging] => 1
    [author-link] => 0
    [comment-author-link] => 0
    [user-register] => 1
    [user-register-email-confirm] => 1
    [register-url] => 0
    [login-url] => 0
    [resetpass-url] => 0
    [replace-avatar] => 1
    [avatars] => 1
    [custom-avatars] => 1
    [signature] => 1
    [rating] => 1
    [rating_title] => 1
    [member_cashe] => 1
    [object_cashe] => 1
    [html_cashe] => 0
    [memory_cashe] => 1
    [seo-title] => 1
    [seo-meta] => 1
    [seo-profile] => 1
    [rss-feed] => 1
    [font-awesome] => 1
    [bp_profile] => 0
    [bp_activity] => 1
    [bp_notification] => 1
    [bp_forum_tab] => 1
    [um_profile] => 0
    [um_forum_tab] => 1
    [um_notification] => 1
    [user-synch] => 0
    [role-synch] => 1
    [output-buffer] => 1
    [wp-date-format] => 0
    [subscribe_conf] => 1
    [subscribe_checkbox_on_post_editor] => 1
    [subscribe_checkbox_default_status] => 1
    [attach-media-lib] => 1
    [debug-mode] => 1
    [copyright] => 0
    [profile] => 1
    [notifications] => 1
    [notifications-live] => 0
    [notifications-bar] => 1
    [goto-unread] => 1
    [goto-unread-button] => 0
    [disable_new_user_admin_notification] => 1
    [option_cache] => 1
    [admin-cp] => 1
)
Array
(
    [font_size_forum] => 18
    [font_size_topic] => 16
    [font_size_post_content] => 14
    [custom_css] => #wpforo #wpforo-wrap {
   font-size: 13px; width: 100%; padding:0px 0px 0px 0px; margin:0px;
}

#wpf-msg-box {
     top: 100px!important;
}
)
Array
(
    [id] => classic
    [name] => Classic
    [version] => 1.0.0
    [description] => Main wpForo Stylesheet
    [author] => gVectors Team
    [url] => http://wpforo.com
    [file] => classic/style.css
    [folder] => classic
    [layouts] => Array
        (
            [1] => Array
                (
                    [id] => 1
                    [name] => Extended
                    [version] => 1.0.0
                    [description] => Extended layout displays one level deeper information in advance.
                    [author] => gVectors Team
                    [url] => http://gvectors.com/
                    [file] => classic/layouts/1/forum.php
                )

[4] => Array
                (
                    [id] => 4
                    [name] => Threaded
                    [version] => 1.0.0
                    [description] => Threaded layout turns your forum to a threads list accented on discussion tree view.
                    [author] => gVectors Team
                    [url] => http://gvectors.com/
                    [file] => classic/layouts/4/forum.php
                )

[2] => Array
                (
                    [id] => 2
                    [name] => Simplified
                    [version] => 1.0.0
                    [description] => Simplified layout looks simple and clean.
                    [author] => gVectors Team
                    [url] => http://gvectors.com/
                    [file] => classic/layouts/2/forum.php
                )

[3] => Array
                (
                    [id] => 3
                    [name] => QA
                    [version] => 1.0.0
                    [description] => Q&A Layout turns your forum to a powerful question and answer discussion board.
                    [author] => gVectors Team
                    [url] => http://gvectors.com/
                    [file] => classic/layouts/3/forum.php
                )

)

[style] => grey
    [styles] => Array
        (
            [default] => Array
                (
                    [0] => #000000
                    [1] => #ffffff
                    [2] => #333333
                    [3] => #555555
                    [4] => #666666
                    [5] => #777777
                    [6] => #999999
                    [7] => #cccccc
                    [8] => #e6e6e6
                    [9] => #f5f5f5
                    [10] => #dadada
                    [11] => #659fbe
                    [12] => #43a6df
                    [13] => #72ccfc
                    [14] => #0099cc
                    [15] => #3f7796
                    [16] => #4a8eb3
                    [17] => #dff4ff
                    [20] => #ff812d
                    [30] => #4dca5c
                    [31] => #00a636
                    [32] => #86ba4c
                    [33] => #6fa634
                    [40] => #ff9595
                    [41] => #ff7575
                    [42] => #f46464
                )

[red] => Array
                (
                    [0] => #000000
                    [1] => #ffffff
                    [2] => #333333
                    [3] => #555555
                    [4] => #666666
                    [5] => #777777
                    [6] => #999999
                    [7] => #cccccc
                    [8] => #e6e6e6
                    [9] => #f5f5f5
                    [10] => #dadada
                    [11] => #e0141e
                    [12] => #ee1a26
                    [13] => #fc979c
                    [14] => #e0141e
                    [15] => #99262b
                    [16] => #d61319
                    [17] => #fff7f7
                    [20] => #30b2a7
                    [30] => #4dca5c
                    [31] => #00a636
                    [32] => #86ba4c
                    [33] => #6fa634
                    [40] => #ff9595
                    [41] => #ff7575
                    [42] => #f46464
                )

[green] => Array
                (
                    [0] => #000000
                    [1] => #ffffff
                    [2] => #333333
                    [3] => #555555
                    [4] => #666666
                    [5] => #777777
                    [6] => #999999
                    [7] => #cccccc
                    [8] => #e6e6e6
                    [9] => #f5f5f5
                    [10] => #dadada
                    [11] => #6ea500
                    [12] => #649e2d
                    [13] => #8dce0c
                    [14] => #447714
                    [15] => #5a7f10
                    [16] => #6ea500
                    [17] => #f8fcef
                    [20] => #ff812d
                    [30] => #4dca5c
                    [31] => #00a636
                    [32] => #ff812d
                    [33] => #f47222
                    [40] => #ff9595
                    [41] => #ff7575
                    [42] => #f46464
                )

[orange] => Array
                (
                    [0] => #000000
                    [1] => #ffffff
                    [2] => #333333
                    [3] => #555555
                    [4] => #666666
                    [5] => #777777
                    [6] => #999999
                    [7] => #cccccc
                    [8] => #e6e6e6
                    [9] => #f5f5f5
                    [10] => #dadada
                    [11] => #fc484c
                    [12] => #fc5050
                    [13] => #fc6565
                    [14] => #ff0000
                    [15] => #ff2c2c
                    [16] => #ff0000
                    [17] => #fff4ed
                    [20] => #30b2a7
                    [30] => #4dca5c
                    [31] => #00a636
                    [32] => #86ba4c
                    [33] => #6fa634
                    [40] => #ff9595
                    [41] => #ff7575
                    [42] => #f46464
                )

[grey] => Array
                (
                    [0] => #000000
                    [1] => #FFFFFF
                    [2] => #333333
                    [3] => #555555
                    [4] => #666666
                    [5] => #777777
                    [6] => #999999
                    [7] => #CCCCCC
                    [8] => #E6E6E6
                    [9] => #F5F5F5
                    [10] => #DADADA
                    [11] => #4C4C4C
                    [12] => #FD4D4D
                    [13] => #FC979C
                    [14] => #FC4242
                    [15] => #FC4C4C
                    [16] => #7E7CA3
                    [17] => #FFF7F7
                    [20] => #FF812D
                    [30] => #4DCA5C
                    [31] => #00A636
                    [32] => #86BA4C
                    [33] => #6FA634
                    [40] => #FF9595
                    [41] => #FF7575
                    [42] => #F46464
                )

[dark] => Array
                (
                    [0] => #000000
                    [1] => #141414
                    [2] => #bbbbbb
                    [3] => #000000
                    [4] => #666666
                    [5] => #bcbcbc
                    [6] => #999999
                    [7] => #585858
                    [8] => #727272
                    [9] => #323232
                    [10] => #dadada
                    [11] => #888888
                    [12] => #33779b
                    [13] => #7eea8d
                    [14] => #777777
                    [15] => #e0e0e0
                    [16] => #cecece
                    [17] => #33779b
                    [20] => #ff812d
                    [30] => #4dca5c
                    [31] => #00a636
                    [32] => #86ba4c
                    [33] => #6fa634
                    [40] => #ff9595
                    [41] => #ff7575
                    [42] => #f46464
                )

)

)
classic

Ask questions. Exchange answers. Welcome to the StudyWise question and Answer forum; a place for you to exchange questions and answers on GCSE, A-Level, University, revision, exams and student life. There’s no better feeling than helping others so if you see a question you know the answer to, be sure chip in. Teachers and students welcome!